This invention relates to a pressure shoe structure particularly for chamfering or glass plate edge bevelling machines and glass processing machines in general.
It is known that chamfering machines are equipped with a plate glass conveyor belt whereon the plate glass is transported edgewise and which comprises a plurality of shoes arranged in a closed loop configuration, the pressing or backing-up shoes being adapted to engage with the plate glass and clamp it against a counter-conveyor during the various processing steps.
In order to accommodate the glass edge processing equipment, it is necessary to leave a spacing between the shoe and the surface on which the plate glass edge rests, so that a standardized design shoe cannot engage with small size plate glass workpieces, such as ones measuring but few centimeters along their sides.
To obviate this limitation, shoes have been proposed which have, at their ends facing the edge of a plate glass workpiece being processed, an extension blade enabling contact engagement even with plate glass workpieces measuring 40.times.40 mm.
That approach has shown not to be always practicable, because the presence of the blades currently in use does not permit an accurate positioning of plate glass workpieces of small size, and involves time-consuming operations for removal, where use of the blade is not required.